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Note: This API doc is automatically generated from the current development version that you can get via Subversion or as a daily snapshot from http://mpg123.org/snapshot. There may be differences (additions) compared to the latest stable release. See NEWS.libmpg123 and the overall NEWS file on libmpg123 versions and important changes between them.
Let me emphasize that the policy for libmpg123 is to always stay backwards compatible -- only additions are planned (and it's not yet planned to change the plans;-).

mpg123 volume and equalizer

Enumerations
enum	mpg123_channels {   MPG123_LEFT = 0x1, MPG123_RIGHT = 0x2,   MPG123_LR = 0x3 }
Functions
int	mpg123_eq (mpg123_handle *mh, enum mpg123_channels channel, int band, double val)
int	mpg123_reset_eq (mpg123_handle *mh)
int	mpg123_volume (mpg123_handle *mh, double vol)
int	mpg123_volume_change (mpg123_handle *mh, double change)
int	mpg123_getvolume (mpg123_handle *mh, double *base, double *really, double *rva_db)

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Enumeration Type Documentation

enum mpg123_channels

Enumerator:

MPG123_LEFT	The Left Channel.
MPG123_RIGHT	The Right Channel.
MPG123_LR	Both left and right channel; same as MPG123_LEFT|MPG123_RIGHT

Definition at line 440 of file mpg123.h.

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Function Documentation

int mpg123_eq	(	mpg123_handle *	mh,
		enum mpg123_channels	channel,
		int	band,
		double	val
	)

Set the 32 Band Audio Equalizer settings.

Parameters:

	channel	Can be MPG123_LEFT, MPG123_RIGHT or MPG123_LEFT|MPG123_RIGHT for both.
	band	The equaliser band to change (from 0 to 31)
	val	The (linear) adjustment factor.

int mpg123_reset_eq

(

mpg123_handle *

mh

)

Reset the 32 Band Audio Equalizer settings to flat

int mpg123_volume	(	mpg123_handle *	mh,
		double	vol
	)

Set the absolute output volume including the RVA setting, vol<0 just applies (a possibly changed) RVA setting.

int mpg123_volume_change	(	mpg123_handle *	mh,
		double	change
	)

Adjust output volume including the RVA setting by chosen amount

int mpg123_getvolume	(	mpg123_handle *	mh,
		double *	base,
		double *	really,
		double *	rva_db
	)

Return current volume setting, the actual value due to RVA, and the RVA adjustment itself. It's all as double float value to abstract the sample format. The volume values are linear factors / amplitudes (not percent) and the RVA value is in decibels.

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